Immortal: Millennium ~ Precedence Publishing (1999)
Battlestar Galactica ~ Margaret Weis Productions (2007)
Starfinder: Beginner Box (boxed set) ~ Paizo (2019)
Omnigon ~ Omnigon Games (1989)
Superhero 2044 ~ Gamescience (1978)
Sigmata: This Signal Kills Fascists ~ Land of NOP (2018)
Currently available as a Pay What You Want pdf from DriveThruRPG.
Leverage ~ Margaret Weis Productions (2010)
MechWarrior (second edition) ~ FASA (1991)